WAR is a newer statistical metric that measures “Wins Above Replacement,” or how many more wins a player has contributed to a team than a bench player or minor-league replacement would be expected to contribute. Based on the way Baseball-Reference calculates WAR (different sites use different formulas), Trout has contributed 10 wins above what a replacement player would be expected to contribute. That is an astonishing number, especially for a guy who didn’t play his first Major League game until April 28.

According to Baseball-Reference, there have only been 9 10-WAR seasons in the last 20 years — five by batters and four by pitchers. Three of them were achieved by Barry Bonds: